TrainingBleeding control
What is a tourniquet?
A tourniquet is a device that stops life-threatening bleeding from an arm or leg by compressing the limb until arterial blood flow stops. What they do, how they work, and when they are needed.
What a tourniquet is
A tourniquet is a device that stops life-threatening bleeding from an arm or a leg by compressing the entire limb until blood stops flowing through it. It is wrapped around the limb above the injury and tightened until the artery underneath is squeezed shut.
That is the whole idea. A tourniquet does not seal a wound or clot blood. It cuts off the supply.
Used correctly on the right injury, it is one of the few interventions an untrained bystander can perform that reliably saves a life.
How a tourniquet works
Blood reaches your hand or foot through arteries that run deep inside the limb, protected by muscle and bone. Direct pressure on a wound works by pressing the damaged vessel against something solid until the body can clot. When an artery is cut and the bleeding is fast, direct pressure often cannot generate enough force in the right place, and the person can bleed to death before clotting does anything useful.
A tourniquet solves that by compressing the entire circumference of the limb. Squeeze hard enough, all the way around, and the artery collapses. Everything below the tourniquet loses its blood supply, and the bleeding stops.
Two things make this work in practice:
Pressure. The tourniquet has to exceed the pressure inside the artery. That is why a tourniquet has to be tightened far past the point of discomfort. A tourniquet that hurts is not necessarily tight enough. A tourniquet that has stopped the bleeding is.
Width. A wide band spreads its force over more tissue and closes an artery at lower pressure than a narrow one. A narrow strap has to be cranked much harder to achieve the same effect, and it cuts into tissue on the way. This is why a shoelace or a bootlace makes a poor tourniquet, and why improvised tourniquets need at least two inches of width to have any chance of working.
Bigger limbs need more pressure. A thigh has far more soft tissue between the surface and the femoral artery than a forearm does, which is why a single tourniquet sometimes fails on a large leg and a second one has to go on above it.
What a tourniquet is for, and what it is not for
Tourniquets work on arms and legs. That is the entire list.
They are the right tool for:
- Arterial bleeding, where blood is spurting or pulsing
- A partial or complete amputation
- Bleeding that soaks through dressings faster than you can apply them
- A wound you cannot locate because there is too much blood
They do not work on:
- The neck, the torso, or the head, because you cannot compress a limb that is not there
- Junctional wounds, meaning the groin crease and the armpit, where the limb meets the body and there is nothing to compress against
Junctional and torso wounds need wound packing with hemostatic gauze and hard direct pressure. That is a different skill, and anyone carrying a tourniquet should learn it as well.
The parts of a modern tourniquet
Most commercial tourniquets share the same four components, whatever the brand.
The strap or band goes around the limb. Its job is to take up all the slack before anything else happens. Most tourniquet failures start here, with a strap that was not pulled tight enough before the mechanism was used.
The buckle or friction adapter holds the strap at the tension you pulled. Routing it correctly matters, and it is the step people get wrong under stress.
The windlass is the rod you twist. Each turn shortens the band and multiplies the pressure. It is a mechanical advantage device, which is what allows one person to generate enough force to close a femoral artery by hand.
The securing clip or gate locks the windlass so it cannot unwind. A windlass that comes loose in transit is a tourniquet that has failed, and it is a documented failure mode across brands.
Some designs also carry a time strap, a blank white tab to write the application time on. Recording that time is not paperwork. It is clinical information the hospital needs to make decisions about the limb.
Types of tourniquet
Windlass tourniquets are the most common and the most studied. A rod twists to tighten a band. The CAT and the SOFTT-W are the two most widely issued examples, and most commercial designs including our own use this principle.
Ratcheting tourniquets replace the rod with a ratchet strap, tightened in clicks rather than turns. Easier for some people to apply, generally bulkier.
Elastic and single-band tourniquets use stretch rather than a mechanism. They are compact and fast. There is less published evidence supporting them on large limbs, and some are not on the committee-recommended lists that military and agency buyers work from. Check what you are buying against those lists if that matters to you.
Pneumatic tourniquets use an inflatable cuff and a pressure gauge, like a blood pressure cuff. They are precise and are what a surgical team uses. They are not field equipment.
Improvised tourniquets are a belt, a strap or a folded triangle of cloth tightened with a stick. They work sometimes. Studies of improvised tourniquets show high failure rates compared to commercial ones. Use one when it is the only option, never as a plan.
Are tourniquets dangerous?
This is the most common question about them, and the honest answer is that they are far less dangerous than the bleeding they treat.
For most of the twentieth century, tourniquets were taught as a desperate last resort, on the belief that using one meant sacrificing the limb. Two decades of battlefield data from Iraq and Afghanistan, where tourniquets were issued and used at scale for the first time in modern history, showed that belief was wrong. Early tourniquet application saved lives, and permanent complications were far rarer than expected.
Properly applied commercial tourniquets rarely cause permanent nerve damage or limb loss when they are on for under two hours. Most civilian emergencies are resolved well inside that window. The risk of waiting is much higher than the risk of applying.
This evidence is why the guidance changed, why tourniquets are now standard issue for police and military, and why the American College of Surgeons built the Stop the Bleed program around teaching civilians to use them.
How long can a tourniquet stay on?
Under two hours is generally considered safe. Between two and six hours, the risk of tissue and nerve damage climbs. Beyond that, the limb is genuinely at risk.
Two rules follow from this:
Write down the time it went on. The hospital needs it, and nobody's memory is reliable during a traumatic injury.
Do not take it off. Once a tourniquet is applied, it stays on until a medical professional removes it in a setting where the resulting bleeding and the metabolic effects of restoring flow to the limb can be managed. Removing one in the field can restart catastrophic bleeding and cause serious cardiac complications.
Do you need training to use one?
You do not need training to be allowed to use one, and in an emergency you should not hesitate because you have not had any. An imperfectly applied tourniquet that stops the bleeding is better than a perfect one that arrives too late.
But applying a tourniquet is a physical skill, not a piece of knowledge, and it degrades under stress. Applying one to your own thigh, one-handed, while bleeding and lightheaded, is much harder than it sounds. The people who do it well have physically practiced it.
Stop the Bleed courses are widely available, often free, and take about ninety minutes. If you carry a tourniquet, take one.
Tourniquets save lives. That's not marketing, that's fact. But the way we use them and the way they're built has changed over centuries. We designed ours with one goal, to make sure you actually carry one. Because a tourniquet in your pocket beats the one left at home on the nightstand or in your glove compartment. The American College of Surgeons makes this urgent. Uncontrolled bleeding is a leading cause of preventable death. And empowering people with simple tools and training saves lives. Now, before we get any further into this video, we want to make one thing clear. This video isn't a how-to guide or training on tourniquet application. Our goal here is to help you understand why these devices work, how they've evolved, understanding their limitations, and what makes each design suited for different situations. In future videos, we'll go hands-on, demonstrating proper use, when and where to apply a tourniquet, and how to integrate these skills into everyday carry and real-world scenarios. For now, think of this as the foundation, the context behind the tool, because understanding how it works is the first step towards using it responsibly. The tourniquet story stretches back over 2,000 years. In the 1600s, a French surgeon named Etienne Morel tied a stick around a cord and twisted it tight, the first known windlass. A century later, Jean-Louis Petit refined the idea into a device with a mechanical screw. For the first time, medicine had a control over pressure and not just pain. It took the industrial wars of the 20th century to push standardization. During World War I, battlefield medicine met industrialized warfare for the first time. Artillery and machine gun fire created massive hemorrhaging injuries, and while tourniquets were issued, their use was inconsistent and often misunderstood. Many soldiers still died from blood loss because medics feared leaving a tourniquet in place for too long. Yet forward-thinking surgeons began documenting cases where rapid, firm applications saved lives. The first real shift from hesitation towards acceptance of the tourniquet as a legitimate life-saving tool. By World War II, tourniquet designs had modestly improved with rubber and webbing versions, but doctrine still lagged behind. Training remained inconsistent, and many were applied too loosely to be effective or so tightly they caused injury. Combat surgeons started realizing that properly applied tourniquets, even for extended periods, could save lives, and that the danger lay more in delayed application than the tool itself. Learn under fire began to lay the foundation for modern combat casualty care. During the 1993 Battle of Mogadishu, U.S. soldiers faced catastrophic extremity injuries and intense urban combat. Modern, one-hand, windless tourniquets that we know today had not yet been developed. The fight exposed a hard truth. Catastrophic bleeding needed immediate, effective control, and existing tools and doctrine weren't enough. That lesson stayed with the community. A decade later, during the global war on terror, those same questions drove research and innovation. Combat medics and trauma surgeons began gathering real data from the field. Not theory, but outcomes. The results were clear. Early tourniquet use saves lives, and when applied correctly, limbs can often be salvaged. Out of that era came two devices that reshaped modern pre-hospital bleeding control. The Combat Application Tourniquet, or CAT, and the Special Operations Forces Tourniquet, or SOFTT. The Combat Application Tourniquet, developed by North American Rescue, used an easy-to-use, one-handed design that could be rapidly self-applied in combat. Its simplicity and accessibility made it the backbone of the CoTCCC recommendation list for years. The SOFTT, designed by TacMed Solutions, refined the concept with all-metal hardware and exceptional durability under extreme conditions. It became the go-to for special operations and high-demand end users. Together, these two designs defined our modern standard for windless tourniquets. Reliable, field-tested, and responsible for saving countless lives. We view them not as competitors, but as pioneers, the foundation on which today's innovators stand. From those designs forward, new generations of tourniquets have continued to evolve. Smaller, lighter, and more carry-friendly. RETQ is part of that lineage, a continuation of a legacy that began centuries ago and was perfected through decades of combat medicine. The modern tourniquet is a result of 2,000 years of trial, bloodshed, and refinement. When we built the ETQ, we didn't try to reinvent physics. We study what works and what people will actually carry. We often get asked about the one-inch width, is it safe to use, and what led us to this design? The answer? This. When we talk about tourniquet design, it's important to start by giving credit where credit's due. The CAAT tourniquet is the gold standard. It has saved countless lives, set the benchmark for field reliability, and remains one of the most proven devices in existence. By designing the ETQ, we study what made the CAAT effective. Specifically, the way its internal constricting band provides the real arterial compression. If you place the CAAT under load on a limb or a foam roller and fold the outer sleeve inward, you'll see that the core band doing the work is about one inch wide. That observation inspired us to build our one-inch ETQ, a minimalistic, skeletonized version of that proven system, designed to be smaller, lighter, and easier to carry every day. We're not claiming to outperform the CAAT. What we're demonstrating is that both designs work on the same mechanical principle, a narrow advantage, generating sufficient circumferential pressure to include arterial flow when applied correctly. Now, for users who need CAAT-C compliance or greater versatility for larger limbs, we also built the ETQ Wide, which adds that half-inch of width, improving performance on larger extremities, and spreading occlusion pressure over a wider surface area to help minimize tissue stress during prolonged use. Same ETQ DNA, broader pressure. zone, faster and more efficient occlusion on larger limbs. Ultimately, the takeaway isn't necessarily that one design replaces the other. It's the understanding that these systems work, how these systems work, and that choosing the right one for your context can save lives. The CAAT and the ETQ both represent different expressions of the same principle, effective, reliable hemorrhage control in the moments that matter most. This isn't a critique of any one device, it's context. Knowing how your gear functions makes you more capable when it matters. As limb circumference increases, occlusion gets harder. That's why stacking tourniquets, two devices, one stacked above the other on the limb, is common. It expands the effective surface area and reduces the required pressure. A wider tourniquet does the same job in one pass, but adds bulk. That's the trade-off. Capability versus carry comfort. A 200-pound soldier and a 120-pound hiker face different realities and different physiology. Arterial occlusion becomes more difficult as your limb circumference increases, but invisible variables like blood pressure, artery depth, and vessel calcification matter too. Test the tourniquet on your own limbs. Every device fails to occlude at some size. Green Beret Nick Lavery's story drives it home. He sustained catastrophic limb trauma overseas, multiple tourniquets, direct pressure from his own hand, and sheer will kept him alive. So, I know my femoral artery has been severed, and we had a ton of medical training leading up to that deployment, and we got a lot of medical training during that deployment, right, in real time. So I know that I have maybe eight, nine minutes left before I'm completely bled out. Okay. Tourniquet. Pull a tourniquet off my kit. I get that up. on, wrench that down as tight as I can, lock in the windlass, and bleeding doesn't stop. It's like visibly still pouring out of my leg. So I grab a second tourniquet, and I slap that on, wrench that down. It's massive stereo. His experience isn't an indictment of any device. It's a reminder that one tourniquet isn't a guarantee. Redundancy, awareness, and training make the difference. A tourniquet stops blood, and with it, oxygen. The longer it stays on, the more tissue you risk losing. Narrower bands concentrate that pressure into nerves and muscle. Wider bands spread it out, buying time and comfort if evacuation takes hours. In an urban environment where help is minutes away, and time to definitive care is typically less than an hour, a compact one-inch ETQ makes sense. In remote or tactical environments, a wide variant gives you margin. Match your gear, and match your environment. Gear isn't magic. Skill beats equipment every time. Whatever you carry, practice with it. Learn to self-apply one-handed. Learn to apply to someone else. In the dark, under pressure, test your tourniquet. Put it on your leg, count your turns. Feel when the pulse stops. That's knowledge that can't be faked. And it's what will matter most when everything else goes wrong. If you live where help is close, the compact ETQ may be all you need. If the mountains are the desert or on deployment, carry a wide, or carry both. Carry multiple. Understand that sometimes one tourniquet isn't enough, and that bleeding control isn't a one-size-fits-all. It's a plan, a mindset, and a responsibility. A tourniquet you carry beats the one you left behind. you
Reading is not practicing
Applying a tourniquet one-handed on your own thigh is a motor skill. It deteriorates under stress unless it has been physically rehearsed.